A new study’s findings suggest a new potential method for cleaning wastewater after use in the textile, cosmetic, or other industries. Researchers from North Carolina State University demonstrated that a synthetic polymer can remove specific dyes from water and that the polymer can be recovered and reused. The findings suggest a new method for cleaning wastewater after it has been used in the textile, cosmetic, or other industries.
“Dyes are used everywhere, including the textile industry, as well as pharmaceuticals, cosmetics, paper, leather, and even medicines,” said Januka Budhathoki-Uprety, an assistant professor of textile engineering, chemistry, and science at NC State and lead author of a paper on the work. “These contaminants can be a significant source of environmental pollution and pose risks to human health if they are not properly removed from wastewater after dyeing and finishing.”
Dyes are used everywhere, including the textile industry, as well as pharmaceuticals, cosmetics, paper, leather, and even medicines. These contaminants can be a significant source of environmental pollution and pose risks to human health if they are not properly removed from wastewater after dyeing and finishing.
Januka Budhathoki-Uprety
In the study, published in ACS Applied Polymer Materials, researchers made a synthetic polymer called polycarbodiimide. The researchers then tested the material’s ability to clean wastewater first by dissolving it in a solvent, and then mixing it with water contaminated with dyes. They tested the polymer solution against a series of 20 anionic dyes, also called acid dyes, which are used in the textile industry. For initial assessments, the researchers did a visual test with the naked eye to see if the polymer worked. The researchers later quantified how well the polymer removed the colorant using UV-Vis spectroscopy.
“We mixed the polymer solution and dye-contaminated water so the polymer in the solution can grab on to the dye. This is a two-phase solution, just like oil and water. The polymer part of the solution grabs onto the dyes,” Budhathoki-Uprety said. “Then we were able to easily separate the clean water from the contaminated solution mixture by draining it out, similar to separation of water from a mixture of oil and water.”
All but four of the 20 acid dyes tested were removed by the polymer solution. Furthermore, they discovered that the polymer could be recovered in minutes. They discovered dye properties (related to their molecular structures) that influenced whether the polymer worked or not.
“We discovered that the polymer solution can remove dyes from contaminated water, and that we can recover the polymer and reuse it to remove dye from contaminated water,” Budhathoki-Uprety explained.
In the future, researchers hope to create a polymer library that will be able to work with a wider range of dyes. They also want to create a more practical mechanism for cleaning wastewater with polycarbodiimide.
“We’re working on materials that can do the same thing without using the polymer in the solution phase,” Budhathoki-Uprety explained. “You don’t want to have to use a flammable solution if you have a dye spill; you want a solid material that is easier to handle.”
